Lithium-metal selenide organic electrolyte cell

ABSTRACT

THIS INVENTION RELATED TO NOVEL PRIMARY ELECTRIC CELLS (WITH EXTREMELY FLAT DISCHARGE CURVES) COMPRISING POSITIVE ELCTRODES COMPOSED OF METAL SELENIDES WHEREIN THE METALS ARE SELECTED FROM THE GROUP CONSISTING OF SILVER, COPPER, IRON, COBALT, NICKEL, MERCURY, THALLIUM, LEAD, BISMUTH AND THE MIXTURES THEREOF; AND THE NEAGTIVE ELECTRODES COMPOSED OF LIGHT METALS, SAID ELECTRODES BEING DISPOSED IS AN ELECTROLYTE COMPRISING AN ORGANIC SOLVENT SELECTED FROM THE GROUP CONSISTING OF TETAHYDROFURAN, N-NITROSODIMETHYLAMINE, DIMETHYL, SULFITE, PROPYLENE CARBONATE, GAMMA-BUTYROLACETONE, DIMETHYL, CARBONATE, DIMETHOXYETHANE, ACETONITRILE, DIMETHYL SULFOXIDE, DIMETHYL FORMAMIDE, AND MIXTURES THEREOF, AND HAVING DISSOLVED THEREIN SOLUBLE SALTS OF THE METALS, FOR EXAMPLE, THE PERCHLORATES, HEXAFLUOROPHOSPHATES, TETRAFLUOROBORATES, TETRACHLORALUMINATES, HEXAFLUOROARSENATES OF LITHIUM.

Aug. 1, 1972 A ETAL 3,681,144

METAL SELENIDE ORGANIC ELECTROLYTE CELL LITHIUM- 3 Sheets-Sheet 1 Filed Sept. 5, 1970 loo 5 PERCENT 0/5 04 42650 F/GZ INVENTORJ NEY LITHIUM-METAL SELENIDE ORGANIC ELECTROLYTE CELL Filed Sept. 3, 1970 Aug. 1, 1972 N Y ETAL 3 Sheets-Sheet 5 PbSe &7

PERCE/YI' D/S (#42650 mvgmon ATTORNEY 3,681,144 Ice Patented Aug. 1, 1972 3,681,144 corresponded to a 25 hour rate. The initial steady voltage LITHIUM-MET SE EN OR on load was 1.5 volts. The practice open circuit voltage ELECTROLYTE CELL was 2.3 volts. The operating cell potential remained at Ambinda Narayan Needham and Per y 1.5 +0.1 volts throughout the major portion (80%) of Mass" asslgnors m Mallory & Indlan' the cell life. The material utilization was found to be 88% apolis li Sept 3, 1970, Set. 69,272 5 up to the 1.1 volt end point. The cathode reaction was Int. Cl. H01m 23/02 assumed to W U.S. Cl. 136-83 R 15 Claims CuSe+2Li+2e Cu+Li Se The discharge curve is shown in FIG. 1. ABSTRACT OF THE DISCLOSURE (2) Lithium-ferric selenide cell: The open circuit volt- This invention relates to novel primary electric cells age Qt this cell Y found Q e Volts-The dlsehal'ge (with extremely flat discharge curves) comprising 1308p conditions of this cell were similar to that 1n the example tive electrodes composed of metal selenides wherein the metals are selected from the group consisting of silver, The initiel Steady OUtPUtYOItegeWeS1-35 and it did not copper, iron, cobalt, nickel, mercury, thallium lead, change during the useful discharge of the cell, 80% of muth and the mixtures th f; and the negative electrodes stoichiometric capacity. The practical open circuit voltage composed of light metals, said electrodes being disposed was found to be Le volts. The material utilization up to in an electrolyte comprising an organic solvent selected the -Q Volt end P Was found t be 80% based on the from the group consisting of tetrahydrofuran, N-nitroso- 2O followmg cathode dlseharge Ieaetlehi dimethylamine, dimethyl sulfite, propylene carbonate, +2 ++2 gamma-butyrolacetone, dimethyl carbonate, dimethoxyethane, acetonitrile, dimethyl sulfoxide, dimethyl formamide, and mixtures thereof, and having dissolved therein soluble salts of the metals, for example, the perchlorates, hexafiuorophosphates, tetrafluoroborates, tetrachloroaluminates, hexafiuoroarsenates of lithium.

The discharge curve is shown in FIG. 2. The exceedingly high voltage stability (1%) is the special feature of this system.

The theoretical energy densities of this system were calculated to be 327 w.-hr./lb. and 35 w.-hr./in. based on the open circuit voltage of 1.6 volts.

The other Li-metal selenide cells tested, in addition to We have is v r d h t a new Class of inorganic Li/CuSe and Li/FeSe were: Li-nickel selenide, Li-merpounds (which, to our knowledge, have never been s cury selenide, Li-lead selenide and Li-bismuth selenide. as depolarilel's in the batteries) can he used as p The discharge characteristics of all these systems are izers in the organic electrolyte batteries. These materials shown i T b1 1 Th discharge curves f th ll r are metal selenides, -a selenides of pp iron, shown in FIGS. 3 through 6 in the same order as shown muth, lead, silver, cobalt, nickel, mercury, thallium, and b e m e thereof- The Compounds Were never used It is apparent that all these systems are characterized as depolarizers in the conventional acidic and alkaline bat ith the exceedingly steady output voltages, heretofore,

teries because of their instability a d low Voltage ehtlfunattainable in most of the existing systems. The systems,

acteristics in those electrolytes. These deficiencies were i l, are l h r t i d ith hi h olu tri overcome, in this invention, by using organic electrolytes it d th oomp1ete absence of i and lithium anodes. The materials were found to be stable The invention is applicable to all the metal-selenides in th organic electrolytes and exhibit desirable v g which exhibit some degree of electronic conductivity. In

characteristics with the lithium anode. addition to this, the scope of this invention is similar to The Object of the invention is to Provide a Series of the scope of the invention disclosed in copending applicanovel lithium-metal selenide organic electrolyte cell with: ti U S, S r, No, 55,170, fil d J l 15, 1970,

(a) high volumetric and gravimetric energy density, THE SCOPE OF THE INVENTION (b) high material utilization efiiciency,

(6) long Shelf life, This invention is applicable to all pr1mary cells with:

(dl) fexcfet liltiocnally steady output voltage throughout the (1) light metal anodes Li, Na, A1 Mg, Ca, K, and

1 e0 e e no P gassmg dunng the Storage and the (2) organic solvents such as tetrahydrofuran, N-nitroso- Operation of the celldimethylamine, dimethyl sulfite, propylene carbonate, The cathode fabrication, the lithium anode fabrication, dimethyl SultOXide, dimethyl fermamide, gemmebhutyrethe electrolyte and the cell construction are similar to laetehe, dimethyl Carbonate, methyl femlate, buty that described in the invention of copending application formate. acetonitrile, dimethexyethane. d the U.S. Ser. No. 55,170, filed July 15, 1970. three thereof- The performance of the various lithium-metal selenide (3) electrolytes comprising the above solvents and all cells, constructed as above, is described below: soluble salts of Li, Na, K, Mg, Ca, Al, and Be dissolved (1) Lithium-copper selenide cell: The open circuit volttherein. The perchlorates, hexafluorophosphat tetraage of the cell was 3.29 volts. The cell was discharged fiuoroborates, tetra and heXaflHO- using a constant current of 4.5 ma. (1 ma./cm. which roarsenates are particularly suitable.

TABLE L-PERFORMANCE OF Li-METAL SELENIDE CELLS 4.5 ma. constant current, 1 min/em. C.D. 20-30 hr. rate Material Prac- Average utilization Initial tical operating eifieieney, Discharge Cell 0.0.V. 0.0.V. voltage percent Assumed cathodereaction curve Lithium/copper selenide 3.29 1.8 1.55:0.10 88 CuSe+2Li+2e- Cu+LhSe Figure 1. Lithium/iron selenide... 3.30 1.6 1.35=|=0.05 FeSez+2Ll++2e- FeSe+LizSe Figure2. Lithiumlnickelselenide 3.00 1.7 1.40:1:010 88 NiSe+2Li++2e Ni+LizSe Figure 3. Lithium/mercury selenide. 3.26 1.9 1.60:1:020 65 HgSe+2Li++2e- Hg+LioSe Figure 4. Lithium/lead selenide-.. 2.78 1.5 1.20=I=0.10 PbSe+2Li++2e- Pb-|LizSe Figure 5. Lithium/bismuth selenide 3.20 1.8 1.45=|:0.05 100 BizSe3+6Li++6e Bi+3Li2Se Figure 6.

What is claimed is:

1. A high energy density primary cell comprising a positive electrode composed of the selenides of silver, copper, iron, cobalt, nickel, mercury, thallium, lead and bismuth and their mixtures; a negative electrode composed of a light metal, said electrodes being disposed in an electrolyte comprising an organic solvent selected from the group consisting of tetrahydrofuran, N-nitrosodimethylamine, dimethyl sulfite, propylene carbonate, gamma-butyrolactone, dimethyl carbonate, dimethoxyethane, acetonitrile, dimethyl sulfoxide, dimethyl formamide, and mixtures thereof, and having dissolved therein soluble salts of the light metals.

2. The cell in claim 1 wherein the electrolyte is composed of a solution of lithium perchlorate in tetrahydrofuran and the negative electrode is composed of lithium.

3. The cell in claim 2 wherein the positive electrode is composed of a mixture of silver selenide and a conductive diluent.

4. The cell in claim 2 wherein the positive electrode is composed of a mixture of copper selenide and a conductive diluent.

5. The cell in claim 2 wherein the positive electrode is composed of a mixture of iron selenide and a conductive diluent.

6. The cell in claim 2 wherein the positive electrode is composed of a mixture of cobalt selenide and a conductive diluent.

7. The cell in claim 2 wherein the positive electrode is composed of a mixture of nickel selenide and a conductive diluent.

8. The cell in claim 2 wherein the positive electrode is composed of a mixture of mercury selenide and a conductive diluent.

9. The cell in claim 2 wherein the positive electrode is composed of a mixture of thallium selenide and a conductive diluent.

10. The cell in claim 2 wherein the positive electrode is composed of a mixture of lead selenide and a conductive diluent.

11. The cell in claim 2 wherein the positive electrode is composed of a mixture of bismuth selenide and a conductive diluent.

12. The cell in claim 1 in which the light metal is selected from the group consisting of Li, Na, K, Ca, Be, Mg and Al.

13. The cell in claim 1 in which the soluble salt is selected from the group consisting of the perchlorates, hexafiuorophosphates, tetrafluoroborates, tetrachloroaluminates, and hexafluorophosphates of the light metals.

14. The cell in claim 1 in which the soluble salt is selected from the group consisting of the perchlorates, hexafluorophosphates, tetrafiuoroborates, tetrachloroaluminates and hexafiuorophosphates of Li.

15. The cell in claim 2 wherein the conductive diluent is graphite.

References Cited UNITED STATES PATENTS 2,081,926 6/1937 Gyuris 136-83 R 3,468,716 9/1969 Eisenberg 136-100 3,508,966 4/1970 Eisenberg 136-6 3,562,017 2/1971 Lyall 136-137 3,578,500 5/1971 Maricle et al. 136-6 ANTHONY SKAPARS, Primary Examiner US. Cl. X.R. 

